I really think Canon has too many 18mp sensor on stock and it's just finding a way to use them and the Eos M isn't selling enough; so they are trying with a different body around the same sensor.
7d, 550d, 60d, 600D, 650D and eosM. Now 100D.. 7 cameras in 4 years with the same sensor and unfortunately for us canon lovers it makes sense. Canon is doing an internal scale economy, exactly what Sony is doing selling sensors to the other brands. I said Unfortunately for us because the replacements are slower then Sony.
Because I see it more an economical and not technical problem I am pretty sure the next generation will be greater then the competition especially at the beginning. It has to be if they wanna use it till 2016!

Good point but don't forget Sony is still using the same 16mp sensor technology in most of their own models as well. (Nex-5n, Nex-C3, Nex-5r, Nex-F3 Nex-6, Nex-3n, A55, A35, A57, A580, Nex-VG20, Nex-EA50 and Nex-VG30) Not to mention all the Nikon and Pentax cameras using it.
Although, like Canon, their most recent iterations are technically different with an integrated phase detect sensor.
Canon is not just competing with Nikon, in fact they said they were more concerned with Fuji and Sony as a sensor manufacturer. I'm sure Canon is doing this for financial reasons; they put a lot of time and money into making that 18mp sensor so they're trying to get their money back and make enough of a profit to fund a new design that's competitive with the future mainstream sensors. So they need to save/make enough money to compete with Sony's new sensor tech since Sony seems to be doing the best at optimizing funding.
I hope Canon can make a competitive sensor because I find their cameras the most enjoyable to use.